Field of the Invention
The present invention relates to a substrate for an ink jet recording head configured to eject ink in accordance with an ink jet recording method to produce a record on a recording medium.
Description of the Related Art
In the ink jet recording methods, a method in which thermal energy is used to bubble and eject ink enables high density integration of nozzles configured to eject ink, and can realize highly precise recording at high speed. An ink jet recording head adopted in this type of recording method typically includes a plurality of ink ejection orifices, an ink liquid path communicating to the ejection orifices, and energy generating elements such as electrothermal converting elements configured to generate thermal energy for bubbling the ink. Insulation of the energy generating elements from the ink and insulation among the energy generating elements are secured by an electrically insulating protective layer. Drive of an energy generating element generates thermal energy to rapidly heat the ink at an ink contact portion (thermally acting portion) at the top of the energy generating element to bubble the ink. Pressure accompanying the bubbling ejects the ink through an ejection orifice to enable production of a record on a recording medium such as paper.
In steps of manufacturing a substrate for an ink jet recording head, the insulating protective layer may be broken due to electrostatic discharge (referred to as ESD event). Breakdown of the insulating protective layer on a wiring layer causes problems such as shortening of the life of the substrate for an ink jet recording head and lowering of print quality. As a measure against this, in Japanese Patent Application Laid-Open No. 2001-080073, there is disclosed reducing sensitivity to an ESD event by coupling conductor regions on the insulating protective layer.